基于格子玻尔兹曼的两相闭式环路热虹吸研究

两相闭式环路热虹吸(CLTPT)形成定向循环的动力来源是重力在蒸发器和冷凝器之间形成的压力差。本文通过修改Gong-Cheng相变LBM模型中重力项计算方式,成功模拟了CLTPT在沸腾和凝结相变共同作用下产生的自驱动现象,揭示了不同充液率下的多种两相流型的存在。发现对于本文设计的热虹吸管结构,在初始状态液相覆盖全部蒸发段的前提下,充液率越小,CLTPT的周期性越复杂,越难达到稳定运行状态,系统自循环时均质量流量更小,同时蒸发段时均温度更低。

A Research of Closed Loop Two-Phase Thermosyphon Based on Lattice Boltzmann Method

The pressure difference between evaporator and condenser caused by gravity is the dynamic source of directional circulation of the Closed Loop Two-Phase Thermosyphon(CLTPT).In this paper,by modifying the gravity term of the Gong-Cheng’s model for phase change lattice Boltzmann method,the self-driving phenomenon of CLTPT under the influence of boiling and condensation phase change is successfully simulated,and various two-phase flow patterns under different filling rates are revealed.For the thermosyphon designed in this paper,when the liquid phase always covers evaporator at initial state,by decreasing the filling rate,the CLTPT system is more difficult to achieve dynamic stable state,its periodicity is more complex.time average mass flow rate is smaller and time average temperature at the heating areas are lower.